William o



(No Model.)

W. 0. CHRISTBNSEN.

CENTER BOARD.

Patented ApIzZll, 1883.

ATTORNEYS.

UNITED STATESV PATENT OFFICE.

\VILLIAM O. OHRISTENSN, OF MARSHFIELD, OREGON.

CENTER-BOARD. y u

SPECIFICATION forming part of Letters Patent No. 276,353, dated April 24, 1883.

ApplicationledJ'anuaryQ, 1883. (No model.)

To allfwhom it may concern:

Be it known that I, WILLIAM 0. UHRISTEN- SEN, of Marshfield, in the county of Goos and State ot` Oregon, have invented a new and usel'ul Improvement in Center-Boards for Vessels, of which the following is a full, clear, and exact description.

The' object ot' my invention is to provide a center-board for vessels that can be more readily operated, and which will give a greater area of resistance than center-boards of ordinary construction and arrangement.

Reference is to be had to the accompanying drawings, forming a part of this specication, in which similar letters -of reference indicate corresponding parts in all the figures.

Figui e l is a side elevation, partly sectional, ot' a vessel provided with my improved center-board. Fig. 2 is a transverse section at the keel, showing the board in the lowered position. Fig. 3 is a similar view, showing the board raised. Fig. 4 is a cross-section ot' one of the rods extending to the center-board. Fig. 5 is a cross-section through one of the wells on the line .fr .o ot' Fig. 3; and Fig. 6` is a detail showing the connection of the rods with the center-board.

A is the keel, and B the keelson, ofthe vessel. O is the well for the rods extending through the bottom of the vessel at each side of the keel, and closed over the top of the keelson to form a chamber,in which the rods and cross-bars rise and fall. From the top ot' the well tubes a extend to the top of the main deck, or to any suitable height.

b b are rods extending through the wells C, and connected above the keelson by crossbars c; and the rods b Z1 may also be connected by suitable cross-rods at the bottom ot' the boards; and f are rods extending from the cross-bars c up through the tubes a, for use in raising and lowering the center-board. d are the boards attached to the lower ends of the rods b by means of bolts e, the holes through which the lower bolts c pass beingoblong, so

as to permit play ot' the bolts when either end is raised independent of the other. The rods 'b are of the form in crosssection shown in Figs. 4 and 5.4 Between the two end rods by which the center-board is raised and lowered are guide-rods h h, of similar construction and arrangement, these guide-rods, however, extending only to the top of the keelson. In

their after ends for being raised or lowered by means of the rod, as described, and, if desired, one board at one sideof the keel may be used in place of two. The faces of the boards are to be filled out or made flush with the outside of rods b, to cause them to pass easily through the water. The rodsf are to be provided at their upper ends with suitable devices for the attachment of tackle for raising the centert boards.

I do not confine myself to the exact'form in cross-section of the lower parts of the wells C, as shown, as the same may be of any convenient-form, and can be formed as guides for the rods b at the bottom side of the planking only, and may also be provided with stuffing-boxes for the purpose ot' keeping water from entering the wells. By this construction and arrangement ot the center-boards a vessel is not weakened by the necessity of cutting away the timbers to receive the center-boards. N The boards being entirely below the vessel, only the planking is cut to receive the tubing for the rods, and at the same time the boardi'urnishes a large area of resistance, takes up no cargo room, and can be more readily manipulated.

I am aware that it is not new to place center-boards on each side of the keel, or to raise and lower a center-board by means somewhat .similar to mine; but

What I do claim as new and of my invention is y t l. The combination, with the well O, the keelson B, and the keel A, of the tube a, extending to the deck, the rods b Vb, connected above the keelson by bars c and at the bottom 9 of the keel, and the rodsf, extending from the cross-bars c up through tube a, as and for the purpose specilied.

V6s i 2. The boards d, having oblong holes, and Y I 'thereby being provided with play on the lower bolts c when either end is raised independ ently ot' the other, as shown and described. WILLIAM O. GHRISTENSEN. Witnesses:

A. NASBURY, R. V. PIERCE.

IOO 

